Which smokers report most relief from craving when using nicotine chewing gum?

Seventy-seven smoker clinic clients who managed at least 2 weeks of smoking abstinence while chewing 2 mg nicotine gum reported the degree to which the gum reduced their craving for cigarette, their daily gum consumption and the extent of urges to smoke despite the gum. Greatest relief from craving by the gum was reported by smokers with higher pre-abstinence expired-air carbon monoxide (CO) concentrations and higher "stimulant" and "dependent" scores on a smoking motivation questionnaire but not greater usual daily cigarette consumption. Gum consumption correlated positively with expired-air CO, usual daily cigarette consumption, and "stimulant" and "dependent" smoking scores. Despite the gum, urges to smoke and difficulty not smoking were reported and the severity of these was associated with "indulgent", "stimulant" and "dependent" smoking scores but not CO or usual daily cigarette consumption. The results are discussed in terms of the possible role of pharmacological and non-pharmacological factors in craving.